Which term describes load imposed through the center of the material?

• A. Eccentric load
• B. Axial load
• C. Torsion load
• D. Shear force

Answer: (B)

Axial load is a force that runs along the member’s centerline, so the line of action passes through the centroid. When the load acts through the center, it creates tension or compression along the length without introducing bending moments, leading to a uniform change in length rather than a curved deformation. That straight-through, centerline action is what defines an axial load.

If the force were offset from the center, it would create a bending moment in addition to any axial effect, which is what happens with eccentric loading. A twisting or torque about the axis appears when the load causes rotation along the member’s length, which is torsion. A shear force acts parallel to the cross-section and causes sliding between layers, producing shear stresses rather than a pure axial stress along the length.

So, the term that describes a load imposed through the center of the material is axial load.